Calculating Street Intersection Density with QGIS

Road crossing point thickness is a huge estimation for metropolitan organizers and researchers to assess the organization and transparency of road networks in a given district. QGIS, a notable open-source Geographic Information Structure (GIS) programming, gives indispensable resources for spatial examination. In this instructional exercise, we will direct you through the process of calculating street intersection density using QGIS.

Prerequisites:

• QGIS installed on your computer.  
• Access to street network data for your study area.
• Administrative boundary data (e.g., city or neighborhood polygons).

Steps:

1. Load Data:

1. Open QGIS and create a new project.
2. Load your street network data and administrative boundary data into QGIS. You can use shapefiles or other compatible formats.

2. Line Intersection:

1. Click on the "Vector" menu, then select "Geoprocessing Tools" and choose "Intersection."
2. In the "Input Layer" dropdown, select your street network layer.
3. In the "Overlay Layer" dropdown, select the same street network layer.
4. Choose a suitable name and location for the output file.
5. Click "Run" to execute the intersection operation.

This step will create a new layer with points representing the intersections of the street network.

3. Create Grid:

1. Click on the "Vector" menu, then select "Research Tools" and choose "Create Grid."
2. In the "Grid Type" dropdown, choose "Polygon."
3. Adjust the extent and spacing parameters based on your study area.
4. Set a name and location for the output grid layer.
5. Click "Run" to generate the grid.

4. Points in Polygon:

1. Click on the "Vector" menu, then select "Analysis Tools" and choose "Points in Polygon."
2. In the "Points Layer" dropdown, select the intersection points layer.
3. In the "Polygons Layer" dropdown, choose the grid layer.
4. Specify a name and location for the output layer.
5. Click "Run" to perform the analysis.

This step will attribute each grid cell with the count of street intersections within its boundaries.

5. Calculate Density:

1. Open the attribute table of the output layer.
2. Add a new field for density, using the field calculator.
3. Calculate density by dividing the count of intersections in each grid cell by the area of the cell.
4. Save the edits and close the attribute table.

6. Visualization:

1. Style the grid layer based on the calculated density values.
2. Use a color ramp or graduated symbols to represent different density levels.
3. Add a legend and any additional map elements to enhance the visualization.